Color photography structure



Aug. 9, 1938. R. s. POTTER 125,137

' COLOR PHOTOGRAPHY STRUCTURE Filed Dec. 1o, 195e DHEsn/E SqPPoT Cam/00LWwf? .Sup/20er vBack/NG, L/qn 5ms/rmi .Lm/aes /-SATTORNER Patented Aug.9, i938 4(liniaal) STATE coLon PHOTOGRAPHY STRUCTURE Rowland S. Potter,Brightfordlieights, NY., as-

signor to Defender Photo Supply Company, Incorporated, Rochester, N. Y.,a corporation of New York Application December 1 2 claims.

Thisv invention relates to a color photography structure, and has to domore particularly with a film pack or plate of the type that includes a1 series of lightsensitive or emulsion layers' which 5 are responsive todifferent colors and are held in superposed relationship one upon theother during exposure, either with or without ilteringy layersinterposed between the light sensitive` layers.

A principal object of the invention is to afford a photographic filmpack or plate in which the light sensitive layers are held togetherclosely without any'air space between them during exposure so that sharpand distinct definition of the subject on the negatives is obtained,land which permits ready separation of the light sensitive layers afterexposure so that prints can be made from the several negativesindependently of each other.

In a more specific aspect, the invention has for its object to provide aphotographic lm pack or plate for color photography in which the severallight sensitive layers are united by an adhesive or cementitioussubstance spread over the adjacent surfaces of the emulsion or lightsensitive layers and acting to hold them in close union during exposure.The 'adhesive or cementitious substance is` of a transparent nature andof suchcharacter as to permit pulling apart or otherwise separating theseveral sensitive layers after exposure, so that they may .be 'printedindependnaently, such separation of the layers beingpossi-l ble withoutresorting to dark `room treatment or delicate handling of the illln.v

To .these and other ends, the invention cons`i'sts in the constructionand arrangement that f will appear clearly from the followingdescription when read in conjunction with the accompanying drawing, thenovel features being pointed outin the claims following thespecification. In the drawing:

Fig. 1 is a sectional view of a photographic illm showing one embodimentof the invention, and

Fig. 2 is a similar view illustrating a modified arrangement where alter layer is used.

. For a complete understanding of the 'inven' tion, it will be helpfulto have a knowledge of the known types of color photography nlm. In oneY form of such film, the several layers sensitive to cement or naturalcohesion and may notbe separated. This-.type of construction is suitableonly for transparencies, and does notI permit making prints'fromthenegatives. l

In another type `of film, the several emulsion different colors are heldtogether permanently'b'y 0,1936, serial No. 115,131

or light sensitive layers are held superposed one on the other duringexposure by Vmechanical pressure, and without the interposition of anycementing material between the layers. This form of construction is opento the objection that close contact betweenv the light sensitive layerscannot be had and a certain amount of air is poeketed between theadjacent surfaces of the light sensitive layers, resulting inlack ofclear definition or distinctness of the subject. on the negatives. l

In a third type of film, the light sensitive layers are held togetherduring exposure by cement such ascertain forms of wax, which can beremoved to separate the layers after exposure, and before development.To do this, it is necessary to subject the i'llm to heat, solvents, orboth, and these operations must be performed in darkness since the lmhas not been developed, making the procedure difficult and onewhich hasnot gone beyond the experimental stage, or proved commerciallysuccessful.

According to my invention, the emulsion or light sensitive layers areheld together by means that avoids pocketing air between the adjacentsurfaces of the layers, while holding them in close contact, andpermitting both exposureand development of the several layers as a unitand ready separation thereof after development for independent printing.

One practicalway of accomplishing this consists in the use of atransparent cementitious or adhesive substance such for example as awater solution of soap which is liquid-permeable to allow penetration ofthe developing liquids to the v several layers and which adheres lesstightly than gelatin layers 'adhere to each other, in order to permitsubsequent separation ofl the layers, as

nitrate or cellulose acetate, while 2 indicates a gelatin or colloidalbacking conventionally used to retain the film in a iiat state.

nate the emulsion or light sensitive layers, respectively sensitive tothe primary colors.

1,1 designates i a support or base which can beof cellulose I, l and{desig- 'The light sensitive layer 3 adJacentto the base I ispermanently attached thereto, while i designate illms or layers of-cementitious or adhesive substance such as soap arranged between layersland l and between layers 4 and 5. Thus the several layers are held onthe base I as a unit and usualillm base is made, also that one or morefilter layers may be employed if desired.

In Fig. 2, a structure is illustrated embody-I ing a base 1, gelatinbacking 8, emulsion or light sensitive layers 9 III and II, and adhesiveor cementitious substance I2. I3 designatesva illtering layer which maybe arranged between the emulsion layers and I0 and permanently attachedto the latter, acting to permit only red and `green light to comethrough to the light ,sensitive layers III and Ii, the first layer 9nearest the lens being sensitive only to blue light. The third lightsensitive layer. II- may be sensitive to red and blue only.. where thisarrangement is employed, or if desirable, a red filtering layer may beinterposed between the light sensitive layers Il and II.

The use of such filter layers is no diiferent from the known practice inthe manufacture of color photography film. and where a illter layer isemployed, as in Fig. 2, the cementitious or adhive substance Il may beinterposed between the outer lightysensitive layer 9 and the adjacentfilter layer I3, the latter being `permanently secured to the innerlight sensitive layer Il, and the use of the ,gelatin backing,designated at 2 in Fig. 1- and I in Fig. 2. is in accord. withconventional practice and may be omitted, if preferred.

Buch a nlm' or plate can be exposed in the usual manner, andsubsequently developed as a unit, the cementitious or adhesive substancesuch as soap being transparent and liquid-permeable so that thestructure may be subjected tothe usual photographic developing solutionswhich will penetrate all parts of the several light sensitive layers.

After completion of the developing operation,

r the two outer light sensitive layers'can be removed from the remaininglayer which is left permanently attached to the base so that the vto thestripping operation.

The outer` layer l or '9 of the film structure is pressed against theseparate iilm base referred.

. toand -allowed to dry, after which the outer layer will have adheredto the separate film base to a greater degree than the soap attachedsur-- faces adhere to each other. The separate nlm .base can -bestripped or'pulled away and carries with it permanently attached theretothe outer layer s, or s, constituting then an individual' negative whichcan be printed independently of the others.

By the same procedure, another separate dry gelatin coated base isdipped in a weak solution of gelatin or water, andthe remaining illmunit pressed thereagainst, causing adherence of the second layer 4 orIII, which can bepulled laway from the Ithird or 'remaining layer of theillm structure and is permanently attached to its separate film base.The third layer 3 or i I remains attached to its base of the originalillm structure, andthe three sensitized layers or negatives are thenavailable for separate printl ing operations.

The character of the adhesive or cementitious substance is such as topermit ready separation of the several layers when' subjected to astripping operation such as described above, `but it will be understoodthat other methods of separation than that -described may be employed,

and the essential feature of the invention em- .reference to certainstructural embodiments, it

is not confined to the precise disclosures herein,

and this application is intended to cover any Hferent colors, the layersbeing held together and separated only by an extremely thin strippinglayer consisting of a transparentv liquid-permeable adhesive comprisinga soap solution which illls the' space and excludes any air between thelayers, holding said sensitive layersln optical contact and permittingtheir development while secured together and subsequent separation forprinting independently of each other.

2. A color photography structure comprising a base and a plurality oflayers oi material sensitive to diif'erent colors, one of said layersbeing permanently secured to the base andthe remaining layers beingsecured to the first layer and to each other by an extremely thinstripping layer consisting of a transparent liquid-permeable adhesivecomprising a soap solution that fills the space and excludes any airbetween the layers and between said base and the adjacent layer. saidliquid-permeable adhesive acting to hold said sensitive layers inoptical contact and to permit development of the diiferent layers whilesecured together and separation of the layers after development forprinting independentlyof each other. i i ROWLAND B. POTTER.

